More information
Description
GPC INSTRUMENTATION PROCESS d.o.o. has a permit for water exploitation in the geothermal field Zagreb, with an area of54 km2 on which 13 wells have been drilled, two of which are currently in production. Confirmed reserves of the P1 category of geothermal water amount to approximately 10 l/s, while the total reserves of the confirmed and probable P1 + P2 category amount to 77.14 l/s. The company has been heating the Mladost Sports and Recreation Center and the warehouses at the Novi Zagreb Hospital since 1981, and the KIF since 2018. The intention of the concessionaire is to build the heating infrastructure of the future National Children''s Hospital in Blato, for the company MC Plus d.o.o. at the location of Lučko and Mladost, for heating the Stjepan Radić student dormitories and the student campus within the KIF. The business plan of our company also includes the use of chilled water after the delivery of thermal energy in the children''s hospital for the needs of Terme Zagreb, the construction of which is planned west of the hospital. In order to maintain the pressure in the reservoir and meet the ecological criteria, the cooled water will be returned to the reservoir. The required water production capacities of new consumers are about 100 l/s, which exceeds the amount of confirmed and probable water reserves of P1 + P2 category. The required documentation for which funds are requested refers to the preparation of the Geothermal Potential Study in order to increase the capacity to accommodate new consumers. As part of the Study, a test of water injection into the well Sava-1 and tests of interference between wells KBNZ 1A and 1B, Mla-1, -2 and Mla-3 and well Sava-1 will be performed. After obtaining the test results, a 3D model for production/injection simulation will be developed, In order to be able to connect new consumers, technical documentation will be prepared for the heating/cooling infrastructure and the connection to the district heating system.
Summary of project results
The aim of the project was to develop technical documentation for the use of geothermal energy in the exploitation field of geothermal water Zagreb, which will ultimately reflect on the increase in the capacity for the production of thermal energy accumulated in geothermal water. The city of Zagreb is spread over a geothermal reservoir, i.e. a large part of the city''s surface is covered with infrastructure, residential and other buildings, where at an average depth of 1000 m there is a reservoir of hot water with a temperature of 80o C. In addition to the above, approximately one million inhabitants live in the area of the City of Zagreb and its surroundings, who can be potential consumers of geothermal energy or hot water.
In 2023, the annual geothermal water pumping rate was only 9.74 l/s, i.e. a total of 306,845 m3 of geothermal water was produced and heat energy sales in the amount of 8,051.0 MW/year were realized. The low level of utilization of the geothermal reservoir capacity for the current stated purposes opens up a wide possibility of using geothermal energy in the future for heating a number of different facilities in the City and Zagreb County: horticultural centers, newly built residential complexes, the student campus of the Faculty of Kinesiology, the national children''s hospital at the Blato location, then for the use of hot water for health purposes (spas), a water park, and especially the use of water as a balneological resource (spa resorts), and others.
The implementation of the project achieved the goal of the Programme, which is to increase the use of energy technologies with lower carbon emissions and increased security of energy supply, and it was achieved by creating project-technical documentation that is the basis for further implementation of the project. Based on the results of the calculations presented in the geological geophysical study, the reserves of geothermal water are significantly higher than those accepted and confirmed by the competent Ministry (229.45 l/s against 100 l/s).
Throughout the entire project implementation, project management, information and communication activities were carried out. Communication plan was developed and all planned activities were implemented: announcements on the website, three commemorative plaques were installed, posters were created and placed in the facilities, a workshop was held on May 25, 2022 ("Round Table") at the Stjepan Radić Secondary School, a lecture was held in March 2024 at the international student meeting at the Faculty of Geosciences and Geophysics, two workshops for the dissemination of results were held, one in April and the other in June 2024, as well as a project''s final conference. Articles were published in the professional publication NAFTA and PLIN and the project was presented in the eco show EKO ZONA on national television (HRT).
The following project and technical documentation has been prepared:
• Preparation of technical documentation for the geological and geophysical study of the geothermal potential of the Zagreb geothermal field
• Study on geothermal water reserves of the exploitation field "Zagreb Geothermal Field"
• Technical documentation has been prepared for the heating/cooling infrastructure and connection to the district heating system of the Student Center (the "Stjepan Radić" dormitories) and the existing wells of the technological system at the Mladost location
• Technical documentation has been prepared for the heating/cooling infrastructure and connection to the district heating system of the National Children''s Hospital and the existing wells at the Blato location
The project was promoted on the Project Promoter''s website where all relevant information was regularly published to inform the public on the advantages of geothermal energy. The idea was to spread information about the existence of geothermal potential, the benefits, advantages and importance of implementing this project, which was presented through the aforementioned workshops and through press releases and announcements in the media, various portals, TV shows, websites and social media pages of the project promoter about the activities carried out by this project. The public was particularly familiarized with the socio-economic advantages of using geothermal energy as a renewable resource:
- contribution to the energy independence of the Republic of Croatia by applying stable energy capacities from renewable energy sources,
- by substituting fossil fuels with energy from renewable sources, environmental pollution is reduced, which consequently has a positive impact on reducing climate change, which is in line with European directives,
- the use of geothermal energy and hot water is also a contribution to stimulating the development of the local economy through a policy of engaging local companies in the implementation of projects,
- by creating new jobs, and with this, the stay and settlement of the young population in the local area, conditions for positive demographics are created.
Technical documentation has been prepared for the heating/cooling infrastructure and connection to the district heating system of the Student Center "Stjepan Radić" and the existing wells at the Mladost location. A building permit has been obtained, as well as the Student Center''s consent for the connection, and letters of support from the University Rector and the Faculty of Engineering and Technology have been obtained, and the Connection Agreement with the representative of the Stjepan Radić Student Center and the Contract with the contractors have been signed. Also, technical documentation has been prepared for the heating/cooling infrastructure and connection to the district heating system of the National Children''s Hospital and the existing wells at the Blato location. A Preliminary Design "Construction of a pre-insulated pipeline for the connection of the National Children''s Hospital to the Blato technological system, the "Zagreb Geothermal Field" exploitation field" has been prepared, and the consent of the Ministry of the Economy, Energy Administration has been obtained.